This invention relates generally to a method and apparatus for cleaning elongated carding flats of a textile carding machine.
A typical textile carding machine converts fiber stock into a strand of fibers known as sliver. The carding machine receives fibers either in loose form or in the form of a picker lap, or, batt. The fibers are formed into a web by the carding machine, and this web is combed and cleaned of impurities.
A conventional carding machine typically has a carding cylinder, the surface of which is covered with small metallic wires or teeth, known as "clothing," which engage and transport the fiber web. The carding machine also typically includes a series of elongated bars known as "carding flats" which are interconnected at their ends by a chain. Each of the carding flats have on one side small wires, or, clothing. The flats extend across the width of the carding cylinder and are transported along a circuitous transport path, such that during an operative, or, interactive, portion of the transport path, the flats approach and contact from an opposite direction the web being carried by the carding cylinder. During this operative portion of the transport path, the clothing of the flats interacts with the web carried on the carding cylinder to remove debris and fine trash, or, "pepper trash" from the web. In normal operation, the clothing of the flats does not contact the carding cylinder clothing in operative portion of the transport path, but instead, the flats clothing is spaced just slightly from the carding cylinder clothing.
After time, trash and debris build up in the clothing of the flats and must be cleaned out in order for the flats to retain their effectiveness. Various types of devices are known for cleaning carding flats. Such conventional carding flat cleaning systems have often included combs and rotating brushes which mechanically engage the clothing of the flats to remove the fibers, trash, and debris therefrom. Various suction devices have also been used to clean the flats.
For example, U.S. Pat. No. 4,227,285, entitled "Textile Card Cleaning Apparatus," issued Oct. 14, 1980 to Hamrick, discloses a device wherein a plurality of suction hoods are provided on a carding machine above the carding cylinder for drawing trash and debris from the flats. U.S. Pat. No. 3,426,093, entitled, "Card Flat Cleaning System," issued on Apr. 15, 1969 to Rutz, discloses a card flat cleaning system which includes nozzles for blowing air the length of the carding flats, from one end of the carding flats to the other, and a low pressure chamber opposite the nozzles for receiving the trash and debris blown from the carding flats. U.S. Pat. No. 4,353,149, entitled, "Flat Cleaning Systems for a Card," issued Oct. 12, 1982 to Demuth, et al., also discloses a device where suction is used to clean carding flats.
U.S. Pat. No. 4,996,746, entitled, "Flat Cleaning Apparatus for a Card," issued Mar. 5, 1991 to Verzilli, et al., discloses a combination comb, brush, and suction device for cleaning carding flats. The comb, suction device, and brush are reciprocatable about the carding flats during cleaning.
Numerous problems exist with conventional carding flat cleaning systems. Often they are too complex and/or use an excessive amount of energy. Further, such mechanical devices require frequent adjustment to ensure that contact by the combs or brushes with the flat clothing is minimal or eliminated altogether. However, if the clearance between the teeth of the brushes and combs and the flats clothing is too great, then adequate cleaning of the flats will not be achieved. Moreover, brushes and combs tend to become clogged themselves, thereby requiring manual cleaning.
Although manual cleaning of carding flats by pressurized air is known, such a process labor intensive, time consuming and can potentially increase the amount of airborne trash and debris in and around the carding machine. With regard to mechanical cleaning systems such as those which use brushes and combs, the contact of such with the fine wire clothing of the flats tend to cause excessive wear of the flat clothing.